The influence of diabetes mellitus on lumbar intervertebral disk herniation

The Clinical Correlations between Diabetes, Cigarette Smoking and Obesity on Intervertebral Degenerative Disc Disease of the Lumbar Spine

Study Design

Retrospective analysis of a nationwide private insurance database. Chi-square analysis and linear regression models were utilized for outcome measures.

Purpose

The purpose of this study was to investigate any relationship between lumbar degenerative disc disease, diabetes, obesity and smoking tobacco.

Overview of Literature

Diabetes, obesity, and smoking tobacco are comorbid conditions known to individually have effect on degenerative disc disease. Most studies have only been on a small populous scale. No study has yet to investigate the combination of these conditions within a large patient cohort nor have they reviewed the combination of these conditions on degenerative disc disease.

Methods

A retrospective analysis of insurance billing codes within the nationwide Humana insurance database was performed, using PearlDiver software (PearlDiver, Inc., Fort Wayne, IN, USA), to identify trends among patients diagnosed with lumbar disc degenerative disease with and without the associated comorbidities of obesity, diabetes, and/or smoking tobacco. Patients billed for a comorbidity diagnosis on the same patient record as the lumbar disc degenerative disease diagnosis were compared over time to patients billed for lumbar disc degenerative disease without a comorbidity. There were no sources of funding for this manuscript and no conflicts of interest.

Results

The total number and prevalence of patients (per 10,000) within the database diagnosed with lumbar disc degenerative disease increased by 241.4% and 130.3%, respectively. The subsets of patients within this population who were concurrently diagnosed with either obesity, diabetes, tobacco use, or a combination thereof, was significantly higher than patients diagnosed with lumbar disc degenerative disease alone (p <0.05 for all). The number of patients diagnosed with lumbar disc degenerative disease and smoking rose significantly more than patients diagnosed with lumbar disc degenerative disease and either diabetes or obesity (p <0.05). The number of patients diagnosed with lumbar disc degenerative disease, smoking and obesity rose significantly more than the number of patients diagnosed with lumbar disc degenerative disease and any other comorbidity alone or combination of comorbidities (p <0.05).

Conclusions

Diabetes, obesity and cigarette smoking each are significantly associated with an increased diagnosis of lumbar degenerative disc disease. The combination of smoking and obesity had a synergistic effect on increased rates of lumbar degenerative disc disease. Patient education and preventative care is a vital goal in prevention of degenerative disc disease within the general population.

Mapping the association between back pain and type 2 diabetes: A cross-sectional and longitudinal study of adult Spanish twins

BACKGROUND

Back pain and type 2 diabetes often co-occur, resulting in greater impact on people's health and complexity in their care. Plausible causal mechanisms for this association have been proposed, yet the nature of the link remains unclear. We therefore explored the direction of the association between type 2 diabetes and chronic back pain in twins, controlling for genetics and early environmental confounding.

METHODS

2,096 and 1,098 twins were included in the cross-sectional and longitudinal analyses, respectively. Any or severe (≥ 9) low back pain (LBP), neck pain (NP), and spinal pain (concurrent LBP and NP) and type 2 diabetes were investigated. Sequential analyses were performed using logistic regression. Firstly, twins were analysed unpaired (adjusted age and gender): total sample analyses. Then, to control for genetic and shared environmental factors, a co-twin case-control analysis was performed including monozygotic and dizygotic twin pairs discordant for back pain (cross-sectional only).

RESULTS

In the cross-sectional total sample analyses, type 2 diabetes was associated with chronic spinal pain (OR 1.61; 95%CI 1.12 to 2.31), severe chronic spinal pain (OR 3.33; 95%CI 1.47 to 7.53), chronic NP (OR 1.37; 95%CI 1.01 to 1.85), severe chronic NP (OR 2.28; 95%CI 1.24 to 4.21), and severe chronic LBP (OR 1.63; 95%CI 1.00 to 2.64). After further adjustment for genetic and shared environmental factors, none of the associations remained significant. The longitudinal analyses indicated that the presence of type 2 diabetes did not increase the risk of future back pain, or vice-versa, after two to four years.

CONCLUSIONS

Chronic back pain (spinal pain, NP, or LBP) was associated with the prevalence of type 2 diabetes. Associations are stronger for severe cases of pain. Future research should investigate the temporal relationships between these conditions with longer follow up in twins.

Clinical and radiological factors related to the presence of motor deficit in lumbar disc prolapse: a prospective analysis of 70 consecutive cases with neurological deficit

PURPOSE

To analyse the clinic-radiological factors associated with neurological deficit following lumbar disc herniation.

METHODS

A prospective, cross-sectional study was performed in 140 cases of micro-discectomy following lumbar disc herniation. Group 1 included 70 consecutive patients with motor deficit and group 2 (controls) included 70 patients with intact neurology. Motor deficit was defined as the occurrence of motor power ≤3/5 in L2-S1 myotomes. Multiple clinical and radiological parameters were studied between the two groups.

RESULTS

Patients with diabetes (p 0.004), acute onset of symptoms (p 0.036), L3-4 discs (p 0.001), sequestrated discs (p 0.004), superiorly migrated discs (p 0.012) and central discs (p 0.004), greater antero-posterior disc dimension (p 0.023), primary canal stenosis (p 0.0001); and greater canal compromise (p 0.002) had a significant correlation with the development of neurological deficit. The presence of four or more of these risk factors showed a higher chance of the presence of motor deficit (sensitivity of 74%, specificity of 77%). Age, sex, previous precipitating events, severity of pain, smoking, and number of herniations levels did not affect the occurrence of deficit (p > 0.05 for all). Patients with or without bladder symptoms were similar with respect to all clinico-radiological parameters. However, the time delay since the occurrence of deficit was significantly shorter in patients with bladder involvement (p 0.001).

CONCLUSION

Patients with diabetes, acute presentation, central, sequestrated and superiorly migrated discs, high lumbar disc prolapse, and greater spinal canal compromise are predisposed to the presence of motor deficit.

Expression of adiponectin receptors in human and rat intervertebral disc cells and changes in receptor expression during disc degeneration using a rat tail temporary static compression model

BACKGROUND

Adipose tissue is a large endocrine organ known to secret adiponectin, which has anti-diabetic, anti-atherogenic, and anti-inflammatory properties. Adiponectin is widely involved in systemic disease, diabetes mellitus, and cardiac infraction. This study aimed to investigate the involvement of adiponectin in intervertebral disc (IVD) degeneration.

METHODS

Adipose and IVD tissues were obtained from human patients undergoing surgery (n = 4) and from skeletally mature Sprague-Dawley rats (n = 21). Tissues were stained immunohistochemically for adiponectin and adiponectin receptors AdipoR1 and AdipoR2. Changes in adiponectin receptor expression with IVD degeneration severity were then investigated using a rat tail temporary compression model. Rat IVD tissues were stained immunohistochemically with AdipoR1 or AdipoR2, and immunopositive cell percentages were calculated. Rat nucleus pulposus (NP) and annulus fibrosus (AF) tissues were isolated separately and treated with recombinant adiponectin (Ad 0.1 or 1.0 μg/ml) and/or interleukin-1 beta (IL-1β) (0.2 μg/ml) for 24 h. The four groups were as follows: control group (no treatment), IL-1β group (IL-1β-only treatment), IL-1β+Ad (0.1) group (IL-1β and adiponectin [0.1 μg/ml] treatment), and IL-1β+Ad (1.0) group (IL-1β and adiponectin [1.0 μg/ml]). Real-time reverse transcription-polymerase chain reaction was performed to evaluate messenger-RNA (mRNA) expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).

RESULTS

Adiponectin was widely expressed in human subcutaneous and epidural adipose tissue. In rat IVD tissue, adiponectin was not observed in NP and AF. However, both AdipoR1 and AdipoR2 were widely expressed in both human and rat IVD tissues, with no significant differences in expression levels between receptors. Furthermore, expression levels of AdipoR1 and AdipoR2 were gradually decreased with increased IVD degeneration severity. Interestingly, mRNA expression levels of TNF-α and IL-6 were significantly upregulated by IL-1β stimulation. TNF-α expression in the IL-1β+Ad 1.0 group was significantly lower than that in the IL-1β group in both NP and AF cells (P < 0.05). Finally, IL-6 expression was not affected by adiponectin treatment in IVD cells.

CONCLUSIONS

This study investigated for the first time the expression of adiponectin receptors in human and rat IVD cells. The findings indicate that adiponectin produced by the systemic or epidural adipose tissue may be involved in the pathomechanism of IVD degeneration.

The Influence of Common Medical Conditions on the Outcome of Anterior Lumbar Interbody Fusion

STUDY DESIGN

The authors retrospectively reviewed a consecutive series of 231 patients with anterior lumbar interbody fusion (ALIF).

OBJECTIVE

To determine the correlations among common medical conditions, demographics, and the natural history of lumbar surgery with outcomes of ALIF.

SUMMARY OF BACKGROUND DATA

Multiple spinal disorders are treated with ALIF with excellent success rates. Nonetheless, adverse outcomes and complications related to patients' overall demographics, comorbidities, or cigarette smoking have been reported.

METHODS

The age, sex, body mass index (BMI), comorbidities, history of smoking or previous lumbar surgery, operative parameters, and complications of 231 patients who underwent ALIF were analyzed. Regression analyses of all variables with complications and surgical outcomes based on total Prolo scores were performed. Two models predicting Prolo outcome score were generated. The first model used BMI and sex interaction, whereas the second model used sex, level of surgery, presence of diabetes mellitus, and BMI as variables.

RESULTS

At follow-up, the rate of successful fusion was 99%. The overall complication rate was 13.8%, 1.8% of which occurred intraoperatively and 12% during follow-up. The incidence of complications failed to correlate with demographics, comorbidities, smoking, or previous lumbar surgery (P>0.5). ALIF at T12-L4 was the only factor significantly associated with poor patient outcomes (P=0.024). Both models successfully predicted outcome (P=0.05), although the second model did so only for males.

CONCLUSIONS

Surgical level of ALIF correlated with poor patient outcomes as measured by Prolo functional scale. BMI emerged as a significant predictor of Prolo total score. Both multivariate models also successfully predicted outcomes. Surgical or follow-up complications were not associated with patients' preoperative status.

Diabetes Mellitus, a New Risk Factor for Lumbar Spinal Stenosis: A Case-Control Study

OBJECTIVES

This study aimed to determine the prevalence of diabetes mellitus in patients with spinal stenosis and lumbar vertebral disk degeneration, and the correlation of diabetes with these diseases.

STUDY DESIGN

This is a cross-sectional study.

METHODS

This case–control study was performed during 2012–2014 with 110 patients suffering from lumbar spinal stenosis and 110 patients with lumbar disk herniation, who were diagnosed using clinical and radiological evidences. Additionally, 110 participants who were referred to the clinic and did not show clinical signs of degenerative diseases of the lumbar spine entered the study as a control group. Demographic data and medical histories of the patients were collected using checklists.

RESULTS

A total of 50 patients (15.2%) were diagnosed with diabetes, which comprised 32 (29.1%) in the stenosis group, 7 (6.4%) in the lumbar disk herniation group, and 11 (10%) in the control group. The prevalence of diabetes in women with spinal stenosis and women with lumbar disk herniation was 35.9% and 10.3%, respectively, whereas prevalence of diabetes in women was 10.9% in the control group. This difference was statistically significant in the spinal stenosis group in comparison with the controls (P < 0.0001). Conversely, no significant difference was found in men.

CONCLUSIONS

There is an association between diabetes and lumbar spinal stenosis. Diabetes mellitus may be a predisposing factor for the development of lumbar spinal stenosis.

Autophagy: A double-edged sword in intervertebral disk degeneration

Autophagy is a homeostatic mechanism through which intracellular damaged organelles and proteins are degraded and recycled in response to increased metabolic demands or stresses. Although primarily cytoprotective, dysfunction of autophagy is often associated with many degenerative diseases, including intervertebral disc (IVD) degeneration (IDD). As a main contributing factor to low back pain, IDD is the pathological basis for various debilitating spinal diseases. Either higher or lower levels of autophagy are observed in degenerative IVD cells. Despite the precise role of autophagy in disc degeneration that is still controversial, with difference from protection to aggravation, targeting autophagy has shown promise for mitigating disc degeneration. In the current review, we summarize the changes of autophagy in degenerative IVD cells and mainly discuss the relationship between autophagy and IDD. With continued efforts, modulation of the autophagic process could be a potential and attractive therapeutic strategy for degenerative disc disease.

The Selection of Open or Percutaneous Endoscopic Lumbar Discectomy According to an Age Cut-off Point: Nationwide Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To provide an age cut-off of percutaneous endoscopic lumbar discectomy (PELD) for optimal reoperation rate with nationwide population-based data.

SUMMARY OF BACKGROUND DATA

Open discectomy is the standard operation for lumbar herniated intervertebral disk disease (HIVD). PELD has shown noninferior outcome to open discectomy and there is increasing interest with regard to PELD. However, PELD may not be a suitable option for all age groups.

METHODS

We selected 15,817 patients who underwent open discectomy (n = 12,816) or PELD (n = 3001) in 2003 from the Korean Health Insurance Review & Assessment Service (HIRA) database. All patients in the cohort were followed until December 31, 2008, and the minimum follow-up period was 5 years. A time-to-event survival analysis was conducted. The primary endpoint was any type of second lumbar spine surgery during the follow-up period. Minimum P-value approach and a 2-fold cross-validation approach were utilized to determine an age cut-off point.

RESULTS

The optimal age cut-off point was determined as 57 years. PELD for older patients (≥57 years) had a higher reoperation risk during the postoperative 3.4 years (hazard ratio [HR] at 1 yr, 1.75; 2 yr, 1.57; and 3 yr, 1.41). However, the reoperation risk was not higher after PELD for patients younger than 57 years, from 1.9 years, than open discectomy (HR at 2 yr, 0.86; 3 yr, 0.78; 4 yr, 0.70; and 5 yr, 0.63).

CONCLUSION

In the present study, we showed that an age cut-off point of PELD for optimal reoperation rate may be 57 years, based on nationwide population-based data. The reoperation rate does not seem to be higher for patients younger than 57 years after PELD than after open discectomy; however, PELD for older patients should be applied after careful consideration.

LEVEL OF EVIDENCE

3.

Elevated whole blood viscosity in patients with lumbar disc herniation

BACKGROUND

Various vascular risk factors such as smoking, obesity, and diabetes mellitus are associated with hyperviscosity and lumbar disc herniation (LDH). However, the changes of viscosity in LDH have not been examined.

AIMS

The present study was to elucidate 1) the rheological parameter levels in patients with LDH, 2) the risk factors that were related to rheological parameters.

METHODS

Our study evaluated the rheological parameters in 307 cases with LDH and in 307 control subjects. Multiple linear regression analysis was conducted to assess the significant factors for whole blood viscosity (WBV) at low shear rate.

RESULTS

LDH patients had markedly lower physical activity and significantly higher WBV 3 s-1 compared with non-LDH subjects (p < 0.001). Moreover, WBV (3 s-1) tended to increase as physical activity decreased. Multiple linear regression analysis revealed that reduced physical activity was a significant factor contributing to elevated WBV (3 s-1).

CONCLUSIONS

WBV (3 s-1) is elevated in patients with LDH. In addition, reduced physical activity is a significant factor for WBV (3 s-1). Further studies are warranted to determine the role of WBV (3 s-1) in LDH.

Rat Notochordal Cells Undergo Premature Stress-Induced Senescence by High Glucose

Study Design

In vitro cell culture.

Purpose

The purpose of the study was to investigate the effect of high glucose on premature stress-induced senescence of rat notochordal cells.

Overview of Literature

Glucose-mediated increase of oxidative stress is a major causative factor for the development of diseases associated with diabetes mellitus such as senescence. However, no information is available for the effect of high glucose on premature stress-induced senescence of rat notochordal cells.

Methods

Notochordal cells were isolated from 4-week-old rats, cultured and placed in either 10% fetal bovine serum (FBS, normal control) or 10% FBS plus two high glucose concentrations (0.1 M and 0.2 M, experimental conditions) for 1 and 3 days. We identified and quantified the mitochondrial damage (mitochondrial transmembrane potential), reactive oxygen species (ROS) and antioxidants, such as manganese superoxide dismutase (MnSOD) and catalase, for each condition. We also identified and quantified senescence and telomerase activity. Finally, we determined the expression of proteins related to replicative senescence (p53-p21-pRB) and stress-induced senescence (p16-pRB) pathways.

Results

Two high glucose concentrations enhanced the disruption of mitochondrial transmembrane potential and excessive generation of ROS in notochordal cells for 1 and 3 days, respectively. The expressions of MnSOD and catalase were increased in notochordal cells treated with both high glucose concentrations at 1 and 3 days. The telomerase activity declined at 1 and 3 days. Two high glucose concentrations increased the occurrence of stress-induced senescence of notochordal cells by p16-pRB pathways at 1 and 3 days.

Conclusions

Despite compensatory expression of antioxidants, high glucose-induced oxidative stress accelerates stress-induced senescence in rat notochordal cells. This may result in dysfunction of notochordal cells, leading to accelerated premature disc degeneration. The prevention of excessive generation of oxidative stress by strict blood glucose control is important to prevent or to delay premature disc degeneration in young patients with diabetes mellitus.

Physical activity is associated with elevated arterial stiffness in patients with lumbar disk herniation

STUDY DESIGN

A cross-sectional study in a general health examination.

OBJECTIVE

To investigate the relationship between brachial-ankle pulse wave velocity (baPWV) and lumbar disk herniation (LDH).

SUMMARY OF BACKGROUND DATA

Lumbar disk herniation (LDH) is a major cause of low back pain and sciatica. Various vascular risk factors such as obesity, diabetes mellitus, and smoking have been reported to be associated with LDH. BaPWV is an early indicator of subclinical atherosclerosis.

METHODS

A total of 490 participants with LDH and 490 participants without LDH were selected for the evaluation of baPWV. BaPWV was measured using an automatic device. The prevalence of LDH was calculated by the quartiles of baPWV levels. Multiple linear regression analysis was performed to evaluate the risk factors for baPWV.

RESULTS

LDH patients had significantly higher readings of baPWV compared with non-LDH subjects (P<0.001). The prevalence rate of LDH gradually increased according to baPWV quartiles. In addition, the levels of baPWV tended to increase as the frequency of physical activity reduced. Multiple linear regression analysis showed that body mass index, low-density lipoprotein cholesterol, physical activity, and systolic blood pressure contributed to increased baPWV.

CONCLUSIONS

The findings showed that LDH patients had higher baPWV levels. In addition, reduced physical activity was a risk factor contributing to increased baPWV. Further studies are warranted to determine the role of baPWV in LDH.

The relationship between diabetes and the reoperation rate after lumbar spinal surgery: a nationwide cohort study

BACKGROUND CONTEXT

Diabetes is present in 5% to 20% of patients undergoing spine surgeries and is a known risk factor for reoperation. Considering the chronicity of diabetes, its influence on the reoperation rate may differ over time.

PURPOSE

To present the relationship between diabetes and the reoperation rate over time.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

A national health insurance database was used to identify a cohort of patients who underwent an initial surgery for lumbar degenerative disease in 2003 (n=34,918).

OUTCOME MEASURES

The primary end point was any type of second lumbar surgery after fusion surgery (n=4,792) or decompression surgery (n=30,126) during the early (0-postoperative 90 days), short-term (91-365 days), and midterm (1-6 years) periods.

METHODS

All patients were followed up until December 2008. Cox proportional hazards regression modeling was used to assess the adjusted reoperation rates in the diabetic patients.

RESULTS

The incidence of diabetes in the present cohort was 24.5% in the fusion group and 16.9% in the decompression group. Overall, reoperation was performed in 13.2% (631 of 4,792) of the patients after fusion surgery and in 14.0% (4,214 of 30,126) of the patients after decompression surgery. After fusion surgery, diabetes did not make a significant difference in the reoperation rate during the entire follow-up period. After decompression surgery, the reoperation rate was not different during Postoperative Month 3, but diabetic patients showed a 1.2 to 1.4 times higher reoperation rate during postoperative 3 months to 5 years (p<.01).

CONCLUSIONS

The study did not find a relationship between diabetes at the time of surgery and the reoperation rate during the early postoperative period. Thereafter, the reoperation rate was not higher after fusion surgery in diabetic patients, but it was higher after decompression surgery.

Alterations in intervertebral disc composition, matrix homeostasis and biomechanical behavior in the UCD-T2DM rat model of type 2 diabetes

Type 2 diabetes (T2D) adversely affects many tissues, and the greater incidence of discogenic low back pain among diabetic patients suggests that the intervertebral disc is affected too. Using a rat model of polygenic obese T2D, we demonstrate that diabetes compromises several aspects of disc composition, matrix homeostasis, and biomechanical behavior. Coccygeal motion segments were harvested from 6-month-old lean Sprague-Dawley rats, obese Sprague-Dawley rats, and diabetic obese UCD-T2DM rats (diabetic for 69 ± 7 days). Findings indicated that diabetes but not obesity reduced disc glycosaminoglycan and water contents, and these degenerative changes correlated with increased vertebral endplate thickness and decreased endplate porosity, and with higher levels of the advanced glycation end-product (AGE) pentosidine. Consistent with their diminished glycosaminoglycan and water contents and their higher AGE levels, discs from diabetic rats were stiffer and exhibited less creep when compressed. At the matrix level, elevated expression of hypoxia-inducible genes and catabolic markers in the discs from diabetic rats coincided with increased oxidative stress and greater interactions between AGEs and one of their receptors (RAGE). Taken together, these findings indicate that endplate sclerosis, increased oxidative stress, and AGE/RAGE-mediated interactions could be important factors for explaining the greater incidence of disc pathology in T2D.

Effect of high glucose on stress-induced senescence of nucleus pulposus cells of adult rats

Study Design

In vitro cell culture model.

Purpose

We investigated the effect of diabetes mellitus (DM) on senescence of adult nucleus pulposus (NP) cells.

Overview of Literature

DM is a major public health issue worldwide, especially adult-onset (type 2) DM. DM is also thought to be an important etiological factor in disc degeneration. Hyperglycemia is considered to be a major causative factor in the development of DM-associated diseases through senescence. However, little is known about the effects of DM on senescence in adult NP cells.

Methods

Adult NP cells were isolated from 24-week-old rats, cultured, and placed in either 10% fetal bovine serum (FBS, normal control) and 10% FBS plus two different high glucose concentrations (0.1 M or 0.2 M; experimental conditions) for 1 or 3 days. We identified and quantified the occurrence of senescence in adult rat NP cells using senescence-associated-beta-galactosidase (SA-β-Gal) staining. We also investigated the expression of proteins related to the replicative senescence (p53-p21-pRB) and stress-induced premature senescence (p16-pRB) pathways.

Results

The mean SA-β-Gal-positive percentage was increased in adult rat NP cells treated with high glucose in a dose- and time-dependent manner. Both high glucose levels increased the expression of p16 and pRB proteins in adult rat NP cells. However, the levels of p53 and p21 proteins were decreased in adult rat NP cells treated with both high glucose concentrations.

Conclusions

The current study demonstrated that high glucose accelerated stress-induced senescence in adult rat NP cells in a dose- and time-dependent manner. Accelerated stress-induced senescence in adult NP cells could be an emerging risk factor for intervertebral disc degeneration in older patients with DM. These results suggest that strict blood glucose control is important in prevent or delaying intervertebral disc degeneration in older patients with DM.

Chronic ingestion of advanced glycation end products induces degenerative spinal changes and hypertrophy in aging pre-diabetic mice

Intervertebral disc (IVD) degeneration and pathological spinal changes are major causes of back pain, which is the top cause of global disability. Obese and diabetic individuals are at increased risk for back pain and musculoskeletal complications. Modern diets contain high levels of advanced glycation end products (AGEs), cyto-toxic components which are known contributors to obesity, diabetes and accelerated aging pathologies. There is little information about potential effects of AGE rich diet on spinal pathology, which may be a contributing cause for back pain which is common in obese and diabetic individuals. This study investigated the role of specific AGE precursors (e.g. methylglyoxal-derivatives (MG)) on IVD and vertebral pathologies in aging C57BL6 mice that were fed isocaloric diets with standard (dMG+) or reduced amounts of MG derivatives (dMG-; containing 60-70% less dMG). dMG+ mice exhibited a pre-diabetic phenotype, as they were insulin resistant but not hyperglycemic. Vertebrae of dMG+ mice displayed increased cortical-thickness and cortical-area, greater MG-AGE accumulation and ectopic calcification in vertebral endplates. IVD morphology of dMG+ mice exhibited ectopic calcification, hypertrophic differentiation and glycosaminoglycan loss relative to dMG- mice. Overall, chronic exposure to dietary AGEs promoted age-accelerated IVD degeneration and vertebral alterations involving ectopic calcification which occurred in parallel with insulin resistance, and which were prevented with dMG- diet. This study described a new mouse model for diet-induced spinal degeneration, and results were in support of the hypothesis that chronic AGE ingestion could be a factor contributing to a pre-diabetic state, ectopic calcifications in spinal tissues, and musculoskeletal complications that are more generally known to occur with chronic diabetic conditions.

High glucose accelerates autophagy in adult rat intervertebral disc cells

Study Design

In vitro cell culture.

Purpose

The purpose of this study was to investigate the effect of high glucose on autophagy in adult rat intervertebral disc cells.

Overview of Literature

Diabetes mellitus is considered to be an important etiologic factor for intervertebral disc degeneration, resulting in degenerative disc diseases. A glucose-mediated increase of autophagy is a major causative factor for the development of diseases associated with diabetes mellitus. However, no information is available for the effect of high glucose on autophagy in adult intervertebral disc cells.

Methods

Nucleus pulposus and annulus fibrosus cells were isolated from 24-week-old adult rats, cultured and placed in either 10% fetal bovine serum (normal control) or 10% fetal bovine serum plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days, respectively. The expressions of autophagy markers, such as beclin-1, light chain 3-I (LC3-I) and LC3-II, autophagy-related gene (Atg) 3, 5, 7 and 12, were identified and quantified.

Results

Two high glucoses significantly increased the expressions of beclin-1, LC3-II, Atg3, 5, 7, and 12 in adult rat nucleus pulposus and annulus fibrosus cells in a dose- and time-dependent manner. The ratio of LC3-II/LC3-I expression was also increased in a dose-respectively time-dependent manner.

Conclusions

The results suggest that autophagy of adult nucleus pulposus and annulus fibrosus cells might be a potential mechanism for the intervertebral disc degeneration in adult patients with diabetes mellitus. Thus, the prevention of autophagy in adult intervertebral disc cells might be considered as a novel therapeutic target to prevent or to delay the intervertebral disc degeneration in adult patients with diabetes mellitus.

Type 2 diabetes seems not to be a risk factor for the carpal tunnel syndrome: a case control study

Background

Previous studies have shown that the carpal tunnel syndrome seems to occur more frequently in patients with diabetes mellitus and might be associated with the duration of diabetes mellitus, microvascular complications and degree of glycaemic control. Primary aim was to determine if type 2 diabetes can be identified as a risk factor for carpal tunnel syndrome after adjusting for possible confounders. Furthermore, the influence of duration of diabetes mellitus, microvascular complications and glycaemic control on the development of carpal tunnel syndrome was investigated.

Methods

Retrospective, case–control study using data from electronic patient charts from the Isala (Zwolle, the Netherlands). All patients diagnosed with carpal tunnel syndrome in the period from January 2011 to July 2012 were included and compared with a control group of herniated nucleus pulposus patients.

Results

A total of 997 patients with carpal tunnel syndrome and 594 controls were included. Prevalence of type 2 diabetes was 11.5% in the carpal tunnel syndrome group versus 7.2% in the control group (Odds Ratio 1.67 (95% confidence interval 1.16-2.41)). In multivariate analyses adjusting for gender, age and body mass index, type 2 diabetes was not associated with carpal tunnel syndrome (OR 0.99 (95% CI 0.66-1.47)). No differences in duration of diabetes mellitus, microvascular complications or glycaemic control between groups were detected.

Conclusion

Although type 2 diabetes was more frequently diagnosed among patients with carpal tunnel syndrome, it could not be identified as an independent risk factor.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-346) contains supplementary material, which is available to authorized users.

Responses and adaptations of intervertebral disc cells to microenvironmental stress: a possible central role of autophagy in the adaptive mechanism

Intervertebral discs comprise the largest avascular cartilaginous organ in the body, and its nutrient condition can be impaired by degeneration, aging and even metabolic disease. The unique microenvironment brings special stresses to various disc cell types, including nucleus pulposus cells, notochordal cells, annulus fibrosus cells and endplate chondrocytes. These cells experience nutrient starvation, acidic stress, hypoxic stress, hyperglycemic stress, osmotic stress and mechanical stress. Understanding the detailed responses and complex adaptive mechanisms of disc cells to various stresses might provide some clues to guide therapy for disc degeneration. By reviewing the published literatures describing disc cells under different hostile microenvironments, we conclude that these cells exhibit different responses to microenvironmental stresses with different mechanisms. Moreover, the interaction and combination of these stresses create a complex environment that synergistically increase or decrease influences on disc cells, compared with the effects of a single stress. Interestingly, most of these stresses activate autophagy, a self-protective mechanism by which dysfunctional protein and organelles are degraded. It is becoming clear that autophagy facilitates the cellular adaptation to stresses and might play a central role in regulating the adaptation of disc cells under stress. Therefore, autophagy modulation might be a potential therapeutic method to treat disc degeneration.

Accelerated premature stress-induced senescence of young annulus fibrosus cells of rats by high glucose-induced oxidative stress

PURPOSES

Diabetes mellitus (DM) is thought to be an important aetiological factor in intervertebral disc degeneration. A glucose-mediated increase of oxidative stress is a major causative factor in development of diseases associated with DM. The aim of this study was to investigate the effect of high glucose on mitochondrial damage, oxidative stress and senescence of young annulus fibrosus (AF) cells.

METHODS

AF cells were isolated from four-week-old young rats, cultured, and placed in either 10 % FBS (normal control) or 10 % FBS plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days. We identified and quantified the mitochondrial damage and reactive oxygen species (ROS) (oxidative stress). We also identified and quantified the occurrence of senescence and telomerase activity. Finally, the expressions of proteins were determined related to replicative senescence (p53-p21-pRB) and stress-induced senescence (p16-pRB).

RESULTS

Two high glucoses enhanced the mitochondrial damage in young rat AF cells, which resulted in an excessive generation of ROS in a dose- and time-dependent manner for one and three days compared to normal control. Two high glucose concentrations increased the occurrence of senescence of young AF cells in a dose- and time-dependent manner. Telomerase activity declined in a dose- and time-dependent manner. Both high glucose treatments increased the expressions of p16 and pRB proteins in young rat AF cells for one and three days. However, compared to normal control, the expressions of p53 and p21 proteins were decreased in young rat AF cells treated with both high glucoses for one and three days.

CONCLUSIONS

The present study demonstrated that high glucose-induced oxidative stress accelerates premature stress-induced senescence in young rat AF cells in a dose- and time-dependent manner rather than replicative senescence. These results suggest that prevention of excessive generation of oxidative stress by strict blood glucose control could be important to prevent or to delay premature intervertebral disc degeneration in young patients with DM.

Advanced glycation end products in degenerative nucleus pulposus with diabetes

Diabetes mellitus (DM) has been clinically proved as a risk factor of disc degeneration, and the accumulation of advanced glycation end products (AGEs) is known to be potentially involved in diabetes. The purpose of this study is to investigate the effect of AGEs in the degeneration process of diabetic nucleus pulposus (NP) in rats and humans. Diabetic NP cells from rat coccygeal discs were treated with different concentrations of AGEs (0, 50, and 100 µg/ml) for 3 days, and mRNA expressions of MMP-2 and RAGE were measured by real-time RT-PCR. In addition, conditioned medium from NP cells was used to analyze protein expression of MMP-2 activity and ERK by gelatin zymography and Western blot. These experiments were repeated using human intervertebral disc samples. The immunohistochemical expression of AGEs was significantly increased in diabetic discs. In response to AGEs, an increase of MMP-2, RAGE, and ERK at both mRNA and protein expression levels was observed in diabetic NP cells. The findings suggest that AGEs and DM are associated with disc degeneration in both species. Hyperglycemia in diabetes enhances the accumulation of AGEs in the NP and triggers disc degeneration.

Body mass index and musculoskeletal pain: is there a connection?

Background

Back pain is one of the most common complaints that patients report to physicians and two-thirds of the population has an elevated body mass index (BMI), indicating they are either overweight or obese. It was once assumed that extra body weight would stress the low back and lead to pain, however, researchers have reported inconsistencies association between body weight and back pain. In contrast, more recent studies do indicate that an elevated BMI is associated with back pain and other musculoskeletal pain syndromes due to the presence of a chronic systemic inflammatory state, suggesting that the relationship between BMI and musculoskeletal pains be considered in more detail.

Objective

To describe how an elevated BMI can be associated with chronic systemic inflammation and pain expression. To outline measurable risk factors for chronic inflammation that can be used in clinical practice and discuss basic treatment considerations.

Discussion

Adiposopathy, or “sick fat” syndrome, is a term that refers to an elevated BMI that is associated with a chronic systemic inflammatory state most commonly referred to as the metabolic syndrome. The best available evidence suggests that the presence of adiposopathy determines if an elevated BMI will contribute to musculoskeletal pain expression. It is not uncommon for physicians to fail to identify the presence of adiposopathy/metabolic syndrome.

Conclusion

Patients with an elevated BMI should be further examined to identify inflammatory factors associated with adiposopathy, such as the metabolic syndrome, which may be promoting back pain and other musculoskeletal pain syndromes.

Combined anti-inflammatory and anti-AGE drug treatments have a protective effect on intervertebral discs in mice with diabetes

Objective

Diabetes and low back pain are debilitating diseases and modern epidemics. Diabetes and obesity are also highly correlated with intervertebral disc (IVD) degeneration and back pain. Advanced-glycation-end-products (AGEs) increase reactive-oxygen-species (ROS) and inflammation, and are one cause for early development of diabetes mellitus. We hypothesize that diabetes results in accumulation of AGEs in spines and associated spinal pathology via increased catabolism. We present a mouse model showing that: 1) diabetes induces pathological changes to structure and composition of IVDs and vertebrae; 2) diabetes is associated with accumulation of AGEs, TNFα, and increased catabolism spinal structures; and 3) oral-treatments with a combination of anti-inflammatory and anti-AGE drugs mitigate these diabetes-induced degenerative changes to the spine.

Methods

Three age-matched groups of ROP-Os mice were compared: non-diabetic, diabetic (streptozotocin (STZ)-induced), or diabetic mice treated with pentosan-polysulfate (anti-inflammatory) and pyridoxamine (AGE-inhibitor). Mice were euthanized and vertebra-IVD segments were analyzed by μCT, histology and Immunohistochemistry.

Results

Diabetic mice exhibited several pathological changes including loss in IVD height, decreased vertebral bone mass, decreased glycosaminoglycan content and morphologically altered IVDs with focal deposition of tissues highly expressing TNFα, MMP-13 and ADAMTS-5. Accumulation of larger amounts of methylglyoxal suggested that AGE accumulation was associated with these diabetic degenerative changes. However, treatment prevented or reduced these pathological effects on vertebrae and IVD.

Conclusion

This is the first study to demonstrate specific degenerative changes to nucleus pulposus (NP) morphology and their association with AGE accumulation in a diabetic mouse model. Furthermore, this is the first study to demonstrate that oral-treatments can inhibit AGE-induced ROS and inflammation in spinal structures and provide a potential treatment to slow progression of degenerative spine changes in diabetes. Since diabetes, IVD degeneration, and accumulation of AGEs are frequent consequences of aging, early treatments to reduce AGE-induced ROS and Inflammation may have broad public-health implications.

Apoptosis, senescence, and autophagy in rat nucleus pulposus cells: Implications for diabetic intervertebral disc degeneration

This research was aimed to study the mechanisms by which diabetes aggravates intervertebral disc degeneration (IDD) and to discuss the relationship between autophagy and IDD in nucleus pulposus (NP) cells. Sixteen weeks after injecting streptozotocin (STZ), the intervertebral discs (IVDs) were studied by histology, Alcian blue, 1,9-dimethylmethylene blue (DMMB), immunohistochemistry, and RT-PCR to explore the IDD. The apoptosis and senescence of NP cells was investigated by terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay, immunohistochemistry, and Western blot for caspase3, caspase8, caspase9, and p16lnk4A (increased in cellular senescence). The level of autophagy in NP cells was detected by Western blot, immunohistochemistry, and transmission electron microscopy (TEM). The proteoglycan and collagen II in the extracellular matrix and the aggrecan and collagen II mRNA expression in NP cells of diabetic rats were decreased compared with the control group. Diabetes increased apoptosis of NP cells and led to activations of initiators of intrinsic (caspases-9) and extrinsic (caspase-8) pathways as well as their common executioner (caspase-3). Cellular senescence was increased about twofold in NP of diabetic rats. In addition, the Western blot, immunohistochemistry, and TEM demonstrated higher level of autophagy in NP cells of diabetic rats than control rats to a statistically significant extent. These findings support that diabetes induced by STZ can cause IDD by accelerating the apoptosis and senescence of NP cells excluding the overweight influence. And the results suggest that the autophagy may be a response mechanism to the change of NP cells in diabetic rats.

Relationship between lumbar spinal stenosis and lifestyle-related disorders: a cross-sectional multicenter observational study

STUDY DESIGN

A cross-sectional multicenter observational study.

OBJECTIVE

To identify associations between lumbar spinal stenosis (LSS) and lifestyle-related diseases.

SUMMARY OF BACKGROUND DATA

Impaired blood flow as a result of arteriosclerosis facilitates degenerative changes in the spine. However, associations between LSS and lifestyle-related diseases (hypertension, diabetes, and dyslipidemia) remain unclear.

METHODS

Participants comprised 526 patients diagnosed with LSS using the clinical diagnostic support tool and magnetic resonance imaging at 64 facilities. Data on 1218 males and 1636 females in the general population were selected from the 2006 National Health and Nutrition Survey as control data. We investigated the prevalence of lifestyle-related diseases (hypertension, diabetes, and dyslipidemia) and levels of hemoglobin A1c, total cholesterol, and high-density lipoprotein cholesterol. LSS and control groups were divided into 4 subgroups by age (nonelderly, <70 yr old; elderly, ≥ 70 yr) and sex. Statistical analyses were performed to compare patients with LSS and the control group using the χ test or Fisher exact text. Values of P < 0.05 were considered statistically significant.

RESULTS

Among nonelderly patients, proportions of patients with hypertension and diabetes mellitus were higher in patients with LSS than in controls (P < 0.01 each). The proportion of patients with hemoglobin A1c was 6.1% or greater and higher for female patients with LSS than for female controls (P < 0.05). No significant difference in the proportion of patients with dyslipidemia was apparent between the LSS and control groups.

CONCLUSION

After adjusting for age and sex, this study revealed a close association between diabetes and hypertension in 50- to 69-year-old patients with LSS. Physicians should consider the possibility of concomitant hypertension or diabetes mellitus when examining 50- to 69-year-old patients with LSS.

Socioeconomic and physical characteristics of individuals with degenerative lumbar spinal stenosis

STUDY DESIGN

A descriptive study of the association between demographic factors, and physical characteristics, and degenerative lumbar spinal stenosis (DLSS).

OBJECTIVE

To shed light on the association between socioeconomic parameters, physical characteristics, and DLSS.

SUMMARY OF BACKGROUND DATA

Lumbar spinal stenosis is a prevalent and disabling condition in the aging population. DLSS is considered to be the most common type and is essentially associated with disc disease, facet joint arthrosis, ligamentum flavum thickening, and osteophyte formation. Although there is ample information regarding the association between body mass index, cardiovascular disorders, smoking habits, and disc disease, very little is known about their association with DLSS. Data on the association of body physique (e.g., height and weight) and DLSS are limited.

METHODS

Two sample populations were studied. The first included 165 individuals with DLSS (mean age, 64 ± 9.9 yr) and the second 180 individuals without spinal stenosis related symptoms (mean age, 62.5 ± 12.6 yr). An evaluation of the cross-sectional area of the dural sac and degenerative listhesis for all participants was performed using computed tomographic lumbar spine images, obtained by Philips EBW station (Brilliance 64, Philips Medical System, Cleveland, OH). All participants were interviewed to obtain demographic, physical, and health data. Independent t test, Mann-Whitney and χ tests were used to determine the association between parametric and nonparametric variables and DLSS. Logistic regression analysis was carried out to reveal predicting variables for DLSS.

RESULTS

Females with stenosis were significantly heavier and shorter than their counterparts in the control group. We also noticed that they delivered babies more often than those in the control group. Prevalence of individuals experiencing diabetes mellitus was significantly higher in the males with stenosis than control group. In the stenosis group, the frequencies of individuals engaged in heavy manual labor (males) and housekeeping (females) were significantly higher than that of their counterparts in the control group.

CONCLUSION

Heavy manual labor and diabetes mellitus in males and housekeeping (females) play major roles in the genesis of DLSS.

Reoperation rate after surgery for lumbar herniated intervertebral disc disease: nationwide cohort study

STUDY DESIGN

Retrospective cohort study using national health insurance data.

OBJECTIVE

To provide a longitudinal reoperation rate after surgery for lumbar herniated intervertebral disc (HIVD) disease, and to compare the reoperation rates of surgical methods.

SUMMARY OF BACKGROUND DATA

Herniated intervertebral disc disease is the most common cause of lumbar spinal surgery. Despite improved surgical techniques and instrumentation, reoperation cannot be avoided. The reoperation rates were in the range of 6% to 24% in previous studies. A population-based study is less subject to bias; hence, a nationwide longitudinal analysis was warranted.

METHODS

A national health insurance database was used to identify a cohort of patients who underwent first surgery for herniated intervertebral disc disease in 2003 and 18,590 patients were selected. Individual patients were followed for at least 5 years through their encrypted unique resident registration number. The primary endpoint was any type of second lumbar surgery. After adjusting for confounding factors, 5 surgical methods (fusion, laminectomy, open discectomy, endoscopic discectomy, and nucleolysis [including mechanical nucleus decompression]) were compared. Open discectomy was used as the reference method.

RESULTS

Open discectomy was the most common procedure (68.9%) followed by endoscopic discectomy (16.1%), laminectomy (7.9%), fusion (3.9%), and nucleolysis (3.2%). The cumulative reoperation rate was 5.4% at 3 months, 7.4% at 1 year, 9% at 2 years, 10.5% at 3 years, 12.1% at 4 years, and 13.4% at 5 years. The reoperation rates were 18.6%, 14.7%, 13.8%, 12.4%, and 11.8% after laminectomy, nucleolysis, open discectomy, endoscopic discectomy, and fusion, respectively. Compared with open discectomy, the reoperation rate was higher after laminectomy at 3 months, whereas the other surgical methods had similar rates.

CONCLUSION

The cumulative reoperation rate after 5 years was 13.4% and half of the reoperations occurred during the first postoperative year. With the exception of laminectomy, the reoperation rates of the other procedures were not different from that of open discectomy.

Dose- and time-dependent effect of high glucose concentration on viability of notochordal cells and expression of matrix degrading and fibrotic enzymes

PURPOSE

Diabetes mellitus is an important aetiological factor in intervertebral disc degeneration. The disappearance of notochordal cells in the nucleus pulposus is thought to be the starting point for intervertebral disc degeneration. A cellular effect of diabetes mellitus on apoptosis of notochordal cells and intervertebral disc degeneration has been recently reported. However, how the duration and severity of diabetes mellitus affects viability of notochordal cells and intervertebral disc degeneration is still unknown .

METHODS

Rat notochordal cells were isolated, cultured, and placed in either 10 % foetal bovine serum (FBS) (normal control) or 10 % FBS plus three different high glucose concentrations (0.1 M, 0.2 M, and 0.4 M) (experimental conditions) for one, three, five and seven days, respectively. We identified and quantified the degree of proliferation and apoptosis, caspase activities, and cleavages of Bid and cytochrome-c. In addition, we examined the cells for expression of matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs).

RESULTS

Each three high glucose concentrations significantly decreased proliferation and increased apoptosis of notochordal cells from culture days one to seven in a dose-dependent manner. Compared with those of 10 % FBS, caspase-9 and -3 activities and cleavage of Bid and cytochrome-c were significantly increased in each three high glucose concentrations, accompanied by increased expression of MMP-1, -2, -3, -7, -9, and -13 and TIMP-1 and -2.

CONCLUSIONS

High glucose concentration significantly decreased proliferation and increased apoptosis of notochordal cells via the intrinsic pathway with dose- and time-dependent effects. We also found that expression of MMPs and TIMPs was increased with dose- and time-dependent effects. Therefore, these results suggest that aggressive glucose control from an early stage of diabetes mellitus should be recommended to prevent or limit intervertebral disc degeneration.

Alterations in T2 relaxation magnetic resonance imaging of the ovine intervertebral disc due to nonenzymatic glycation

STUDY DESIGN

An in vitro study using ovine intervertebral discs to correlate the effects of increasing advanced glycation end-products (AGEs) with disc hydration evaluated by magnetic resonance imaging (MRI).

OBJECTIVE

To determine the relationship between the level of AGEs and tissue water content in intervertebral discs using T2 relaxation MRI.

SUMMARY OF BACKGROUND DATA

AGEs result from nonenzymatic glycation, and AGEs have been shown to accumulate in the intervertebral disc tissue with aging and degeneration. AGEs can alter biochemical properties, including the hydrophobicity of the extracellular matrix. Because one of the degenerative signs of the intervertebral disc (IVD) is reduced hydration, we hypothesized that increased levels of tissue AGEs contribute to disc hydration. T2 relaxation MRI has been shown to be sensitive to the hydration status of the disc and may be valuable in detecting the changes in the IVD mediated by the increase of AGEs.

METHODS

Thirty-eight IVDs were obtained from 4 ovine spines, and the annulus fibrosis (AF) and nucleus pulposus (NP) tissues were isolated from these discs. The tissues were incubated in either a ribosylation or control solution for up to 8 days to induce the formation of AGEs. T2 relaxation times were obtained from these tissues after ribosylation. These tissues were subsequently analyzed for hydration, proteoglycan, collagen, and AGEs content.

RESULTS

In vitro ribosylation led to the increased accumulation of AGEs and reduced water content in both the AF and NP in a dose-dependent manner, but did not affect the proteoglycan and collagen composition. When analyzed by MRI, ribosylation significantly altered the mean T2 relaxation times in the NP (P = 0.001), but not in the AF (P = 0.912). Furthermore, the mean T2 values in the NP significantly decreased with increasing periods of incubation time (P < 0.001).

CONCLUSION

This study demonstrates that levels of AGEs in the IVD may affect the tissue water content. Moreover, these ribosylation-mediated changes in tissue hydration were detectable using T2 relaxation MRI. T2 relaxation MRI may provide a noninvasive tool to measure in vivo changes in disc hydration that are negatively correlated with the accumulation of AGEs.

Effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in diabetic rats

Object

Diabetes mellitus is thought to be an important etiologic factor in intervertebral disc degeneration. It is known that notochordal cells gradually disappear from the nucleus pulposus (NP) of the intervertebral disc with age by undergoing apoptosis. What is not known is whether diabetes has an effect on apoptotic rates of notochordal cells. The purpose of this study was to investigate the effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in age-matched OLETF (diabetic) and LETO (control) rats.

Methods

Lumbar disc tissue (L1–2 through L5–6), including cranial and caudal cartilaginous endplates, was obtained from 6- and 12-month-old OLETF and LETO rats (40 rats, 10 in each of the 4 groups). The authors examined the NP using TUNEL, histological analysis, and Western blot for expression of matrix metalloproteinase (MMP)–1, -2, -3, and -13, tissue inhibitor of metalloproteinase (TIMP)–1 and -2, and Fas (apoptosis-related protein). The apoptosis index of notochordal cells was calculated. The degree of transition of notochordal NP to fibrocartilaginous NP was classified on a scale ranging from Grade 0 (no transition) to Grade 4 (transition > 75%). The degree of expression of MMP-1, -2, -3, and -13, TIMP-1 and -2, and Fas was evaluated by densitometry.

Results

At 6 and 12 months of age, OLETF rats showed increased body weight and abnormal 2-hour glucose tolerance tests compared with LETO rats. The apoptosis index of notochordal cells was significantly higher in the OLETF rats than in the LETO rats at both 6 and 12 months of age. The degree of transition of notochordal NP to fibrocartilaginous NP was significantly higher in the OLETF rats than in the LETO rats at 6 and 12 months of age. The expression of MMP-1, -2, -3, and -13, TIMP-1, and Fas was higher in the OLETF rats at 6 and 12 months of age. The expression of TIMP-2 was significantly higher in the OLETF rats than in the LETO rats at 6 months of age, but not at 12.

Conclusions

The findings suggest that diabetes is associated with premature, excessive apoptosis of NP notochordal cells. This results in an accelerated transition of a notochordal NP to a fibrocartilaginous NP, which leads to early intervertebral disc degeneration. It remains to be determined if these premature changes are due to hyperglycemia or some other factors associated with diabetes. Understanding the mechanism by which diabetes affects disc degeneration is the first step in designing therapeutic modalities to delay or prevent disc degeneration caused by diabetes mellitus.

Lumbar stenosis and systemic diseases: is there any relevance?

STUDY DESIGN

A retrospective study of spinal stenosis patients admitted to Assaf Harofeh Medical Center Orthopedic Departments.

OBJECTIVE

To assess any correlation between systemic disease and spinal stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar stenosis is a common spinal disease with various etiologies. No findings have been reported correlating spinal stenosis incidence with background diseases, although diabetes mellitus (DM) has been found to play a role in intervertebral disc degeneration and spondylolisthesis.

METHODS

Hospitalization records of patients with spinal stenosis admitted to Assaf Harofeh Medical Center Orthopedic Departments between 1984 and 1993 were checked for background diseases, age, and sex. The data collected were statistically evaluated for any correlation between spinal stenosis and chronic diseases and compared with the data published by the "Israeli Bureau of Statistics" and Israel's largest Health Maintenance Organization's chronic disease survey.

RESULTS

Of 537 patients with spinal stenosis 57% (308) were males and (229) 43% females with an average age of 60+/-14 years. Diseases occurring with a high incidence were hypertension (HTN)-23.2% (compared with 7.8% in the general population), DM-13.6% (5.9%), ischemic heart disease (IHD)-11.9%, and hyperlipidemia-4.4%. Patients with spinal stenosis had no significant age and sex distribution difference compared with the general population and no such difference was found for patients suffering from HTN, IHD, or DM. Isolating the effect of DM on HTN and IHD revealed that HTN was a primary disease whereas IHD was secondary to DM with significant statistical validation (P=0.003).

CONCLUSIONS

To the best of our knowledge this is the first study linking spinal stenosis and DM or HTN. It was found that chronic diseases do not alter the natural age and sex distribution of spinal stenosis. The major question remaining concerns the biologic mechanism linking spinal stenosis and DM or HTN.